Table 3. Cone density and arrangement in eyes with retinitis pigmentosa vs. normal eyes.

		Eyes with RP (14 eyes of 14 patients)	Normal eyes (12 eyes of 12 volunteers)	P *
Age (y)		42.64±12.46	38.17±6.84	0.211
logMAR VA		−0.11±0.07	−0.17±0.06	0.538
0.5 mm	Cone density (cones/mm2)	16,200±3,683	22,237±1,900	<0.001
	Ratio of hexagonal Voronoi domain (%)	39.9±3.1	44.2±2.9	0.002
	Average NND/expected NND	0.67±0.03	0.72±0.02	<0.001
1.0 mm	Cone density (cones/mm2)	13,376±2,840	15,975±1,040	0.021
	Ratio of hexagonal Voronoi domain (%)	40.4±3.4	46.8±4.9	0.002
	Average NND/expected NND	0.66±0.04	0.73±0.02	<0.001

^*Mann-Whitney U test.

VA: visual acuity, NND: nearest-neighbor distance, RP: retinitis pigmentosa.